remove null properties before deploying template

fixes KelvinTegelaar/CIPP#4765

Author: JohnDuprey

Modules/CIPPCore/Public/Entrypoints/HTTP Functions/Email-Exchange/Transport/Invoke-AddTransportRule.ps1

@@ -14,6 +14,9 @@ function Invoke-AddTransportRule {
 
     $RequestParams = $Request.Body.PowerShellCommand | ConvertFrom-Json | Select-Object -Property * -ExcludeProperty GUID, HasSenderOverride, ExceptIfHasSenderOverride, ExceptIfMessageContainsDataClassifications, MessageContainsDataClassifications
 
+    # Remove null properties from payload
+    $RequestParams.PSObject.Properties | Where-Object { $_.Value -eq $null } | ForEach-Object { $RequestParams.PSObject.Properties.Remove($_.Name) }
+
     $Tenants = ($Request.body.selectedTenants).value
 
     $AllowedTenants = Test-CippAccess -Request $Request -TenantList